Email Tracking Pixels

You can, but you have to disable image loading (like any other email client) because any image may have tracking information in it.

I thought Gmail routed images through their servers to avoid pixel tracking?

Does this even work considering Gmail pre-fetches all the images nowadays?

I thought Gmail loaded images when it got the email, not when users opened it? Doesn't this prevent pixels from tracking?

You might want to investigate this further - IIRC a lot of email services retrieve images in advance server side to avoid leaking whether the client has interacted with the email. I might be mistaken here.

Dosn't email clients such as gmail automatically block images though? How do you track it?

Images in email is not bulletproof in any way...

Gmail proxies images, if you send everybody the same image you will get very little information about who is grabbing the image and when (i.e. you'll be able to tell when google (re)populates the cache which gives some small indication that your email is being opened).

Actually gmail proxies all image requests from emails so they would see it too. But yes, point taken.

I always wondered why mail providers don't load all images automatically the moment the mail is received and present a cached image to the users. Wouldn't that make tracking useless?